1. Field of the Invention
This invention relates to a technique for cutting a panel, such as a circuit board or the like.
2. Description of Related Art
In the process of manufacturing circuit boards there are various situations in which it is necessary to cut circuit board panels. One such situation involves separating a large panel partitioned into multiple printed circuit boards. Another situation relates to the fact that many circuit boards carry at least one edge connector for connecting the board to an external system. During circuit board fabrication, the board is punched to create a cut-out in its edge for each connector. Typically, the edge connector cut-outs are only partially formed, leaving a thin web of material in what would otherwise be the opening ("throat") of each cut-out. Typically, these webs are integral with each other, effectively forming an elongated tab at the edge of the board. To fully form the edge connector cut-outs, the tab must be cut, thereby removing the web from each cut-out.
A number of methods and devices are known and available for cutting circuit board panels. Two such methods involve the use of a band saw or router. These methods impart vibrations to the printed circuit board, however. These vibrations propagate across the board and, in turn, may cause damage to the solder junctions electrically connecting the components mounted to the board. Also certain surface mounted components are very susceptible to the vibrations from such a band saw and may be easily damaged thereby.
High precision shearing is an alternative method for performing this cutting operation. This method also produces vibration to the circuit board and stress on solder joints. Further, the nature of the shearing operation causes a stress perpendicular to the cut edge that distorts the circuit board in a manner that produces a tendency for delamination to occur along this cut edge over a period of time.
Moreover, these and other prior art methods of cutting circuit boards panels rely on complicated methods of routing the circuit board into the cutting station. Frequently, this handling of the panels and panel portions involved sensing, gripping, and indexed feeding of the panels and panel portions under the control of a programmable computer or sophisticated hardware device. Thus, there is a need for a technique for cutting a circuit board that avoids the need to off-load and/or re-orient the board to the cutting mechanism and for performing the actual cutting in a manner that minimizes stress to the board's components and connections and further, reduces delamination effects over time.